WO 96/27544 discloses a device for transporting products between different stations. Here, a carriage is provided which has a U-shaped yoke, wherein permanent magnets are formed on the inner sides of the yoke. Within the yoke there are arranged multiple air-core coils which are seated on a support plate. When the air-core coils are electrically energized, a magnetic field forms, which magnetic field interacts with the magnetic field of the permanent magnets of the yoke such that the carriage is subjected to a translatory movement. The air-core coils form an air gap between the permanent magnets. Said gap must be kept small in order to achieve a good action of force. The mechanical strength opposes this and does not permit good strength. The mechanical guide cannot be combined with the coil arrangement in this way. Furthermore, air-core coils have the disadvantage of high magnetic leakage losses, in particular in the case of relatively large dimensions. In general, air-core coils are characterized by low inductivity, which leads to a lower thrust force for a given construction and mode of activation.
U.S. Pat. No. 6,876,107 B2 discloses a transport system. Here, a carriage having a U-shaped yoke is provided, wherein permanent magnets are arranged on inner sides of the U-shaped yoke. Within the U-shaped yoke there are formed two opposing coils. With corresponding energization of the coils, a magnetic field forms which interacts with the magnetic field of the permanent magnets such that the carriage performs a translatory movement. Owing to the high number of coils required, such a construction exhibits high complexity, which leads to high costs for the components and the cabling thereof etc. Furthermore, such a construction requires a considerable amount of installation space.
The known systems are thus disadvantageous in particular in that they require a considerably large installation space and exhibit mechanical instabilities, which can for example lead to disturbing vibrations during operation. Furthermore, the known systems also have the above disadvantages described in conjunction with air-core coils.
Furthermore, the known systems have disadvantages in conjunction with guides for the carriages or vehicles. For example, in U.S. Pat. No. 6,876,107 B2, as a guide, a rail is provided which is integrated directly into a support device of the coils. That is to say in particular that, when the rails become worn and must consequently be replaced, it is necessary to exchange the complete support device together with the coils. Furthermore, it is also not possible here to provide different rails according to the application, that is to say for example for a specific vehicle, without also simultaneously exchanging the support device together with the coils.
In WO 96/27544, the rails for running rollers of the vehicle or of the carriage are arranged independently of the air-core coils, wherein the air-core coils are glued to a support plate. Installation and adjustment of a spacing between the rails and air-core coils are difficult owing to this independent fastening and arrangement. This may for example have the result that a spacing between the rails and the air-core coils cannot be optimally set, which can consequently lead in particular to increased wear and/or a lower motor thrust force.
JP 06165475 A presents a linear motor comprising a stator. The stator comprises a hollow yoke which is assembled from two side walls, a cover and a base. Multiple coils are formed on the two side walls. A printed circuit board is mounted on the coils. A slider as a movable element is formed around the stator, wherein the slider has permanent magnets on walls situated opposite the coils.
US 2008/0036305 A1 presents a linear motor comprising multiple core/winding units which each comprise a core composed of steel and a coil wound around the core. Here, the core/winding units are fastened to holding elements, wherein the holding elements themselves are fastened to a frame.